oracle - What is the meaning of the dot in SQL from statement -

let's have simple query

select name_before_dot.name_after_dot 

what meaning of dot in clause?

is kind of separator or table name dot in it?

mind you, have searched so, threads talking dot in select or where, know related aliases, dot in still mystery me.

this database schema. full three-part name of table is:

databasename.schemaname.tablename 

for default schema of user, can omit schema name:

databasename..tablename 

you can specify linked server name:

servername.databasename.schemaname.tablename 

you can read more using identifiers table names on msdn:

the server, database, , owner names known qualifiers of object name. when refer object, not have specify server, database, , owner. qualifiers can omitted marking positions period. valid forms of object names include following:

server_name.database_name.schema_name.object_name

server_name.database_name..object_name

server_name..schema_name.object_name

server_name...object_name

database_name.schema_name.object_name

database_name..object_name

schema_name.object_name

object_name

an object name specifies 4 parts known qualified name. each object created in microsoft sql server must have unique, qualified name. example, there can 2 tables named xyz in same database if have different owners.

most object references use three-part names. default server_name local server. default database_name current database of connection. default schema_name default schema of user submitting statement. unless otherwise configured, default schema of new users dbo schema.